"Everything is progressing in a normal manner. The reactor is functioning well as per expectations," Dr Sinha told HT.

The approach to criticality started on July 11 after completing all the stipulated statutory and regulatory requirements and obtaining the final clearance from the Atomic Energy Regulatory Board (AERB).

The next step is to increase the reactor power in stages to generate 1,000 MW. "Initially the plant will be synchronised with the southern grid with 400 MW within a period of 30 to 45 days of criticality. Subsequently the power will be increased in a step wise manner to 50%, 75%, 90% and 100% full power after attaining the clearance," he said.

The second Kudankulam unit will attain criticality within eight months from now, Dr Sinha said.

KKNPP unit-1 will increase nuclear power contribution nationally to 5,780 MW. Tamil Nadu will have the lion's share of power generated. This is India's first pressurised water reactor belonging to Light Water Reactor category.

KKNPP Units 1 and 2 are VVER-1000 type reactors set up with technical cooperation with the Russian Federation.

Meanwhile the People's Movement Against Nuclear Energy has decided to observe a Black Day on Monday. "On Monday we will enter our 700th day of protest. We have given an open call to the fishermen to abstain from fishing. We have called a meeting of the community leaders on next Sunday to decide on our next agitation," a spokesperson from the People's Movement Against Nuclear Energy said.